USACO Server Input Discrepancy

Question

I'm retrying the USACO Silver Problem Robot Instructions.

On my computer (Macbook Air M1 2020, MacOS Big Sur version 11.3.1), when I manually input the sample case my program outputs the correct answer. However, on the USACO grading server, it displays:

The following appeared on standard error:
Exception in thread "main" java.util.NoSuchElementException
    at java.base/java.util.Scanner.throwFor(Scanner.java:937)
    at java.base/java.util.Scanner.next(Scanner.java:1594)
    at java.base/java.util.Scanner.nextInt(Scanner.java:2258)
    at java.base/java.util.Scanner.nextInt(Scanner.java:2212)
    at RobotInstructions.main(RobotInstructions.java:33)

For reference, my current code is:

import java.util.ArrayList;
import java.util.Scanner;
import java.lang.Math;

public class RobotInstructions {
    public static void main(String[] args) {
        
        Scanner in = new Scanner(System.in);
        
        int nInstructions = in.nextInt();
        
        int wontx = in.nextInt();
        int wonty = in.nextInt();
        
        ArrayList<int[]> a;
        ArrayList<int[]> b;
        
        int n1;
        int n2;
        
        if (nInstructions%2==0) {
            n1 = (int) nInstructions/2;
            n2 = (int) nInstructions/2;
        } else {
            n1 = ((int) (nInstructions-1)/2);
            n2 = ((int) (nInstructions+1)/2);
        }
        
        /////////////////////////////////
        Scanner in1 = new Scanner(System.in);
        int[][] instructionList = new int[n1][2];
        for (int i = 0; i<n1; i++) {
            int a1 = in1.nextInt();
            int b1 = in1.nextInt(); 
            
            instructionList[i][0] = a1;
            instructionList[i][1] = b1;
        }
        a = subset(n1, instructionList);
        /////////////////////////////////
        /////////////////////////////////
        int[][] instructionList1 = new int[n2][2];
        for (int i = 0; i<n2; i++) {
            int a1 = in1.nextInt();
            int b1 = in1.nextInt(); 
            
            instructionList1[i][0] = a1;
            instructionList1[i][1] = b1;
        }
        b = subset(n2, instructionList1);
        /////////////////////////////////
    
        
        int[] answers = new int[nInstructions];
        
        for (int[] i : a) {
            for (int[] j : b) {
                if (i[0]+j[0]==wontx && i[1]+j[1]==wonty) {
                    answers[i[2]+j[2]-1]++;
                }
            }
        }
        
        for (int i : answers) {
            System.out.println(i);
        }
        
    }
    
    
    
    public static ArrayList<int[]> subset(int n, int[][] instructionList) {
        ArrayList<int[]> sums = new ArrayList<int[]>();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i< (Math.pow(2,n)) ; i++) {
            sb.setLength(0);
            String a = Integer.toBinaryString(i);
            for (int j = 0; j<(n-a.length()); j++) {
                sb.append("0");
            }
            sb.append(a);
            
            String c = sb.toString();
            
            int x = 0;
            int y = 0;
            int amt = 0;
            
            for (int k = 0; k<n; k++) {
                if (c.charAt(k) == '1') {
                    x += instructionList[k][0];
                    y += instructionList[k][1];
                    amt++;
                }
            }
            
            int[] m = new int[] {x,y,amt};
            
            sums.add(m);
            
        }
        return sums;
    }
    
    
}

I would not like any feedback on the efficiency of my program, just the reason why the grading server doesn't like my input format.